I don't see how it was so suprising. The angles, velocities, etc were slightly different, but on something of this scale, I don't know that there
was significant difference in the damage. I could see if 1 got hit by a plane at 20 stories up, and one at 90, but this was pretty close.

The original question was 'what are the chances'. I interpret that to mean 'what is the probability...'. That being the case, the answer is 0.
Since there had never been a collapse of this kind of structure ever before there would be no precedent against which to calculate the probability.
Therefore the answer is 0.

An example: You have a bowl with a random number of black and white marbles in it. You select single marbles and note their color returning them to
the bowl. After some number of selections you can calculate the probability of choosing a black or white marble (based upon your earlier selections).
If asked, 'what is the probability of selecting a red marble your answer would be: 0. Never happened before so has 0 probability.

Originally posted by shindigger
But the towers fell in an IDENTICAL manner.

No they didn't, you've already identified that the tower that was hit first fell later so there must have been some diferent mechanics at work in
some respect at least.

However, two essentially identical structures were damaged in very similar ways so a very similar failure mode could well be expected although it
would be by no means certain.

As for probability well it was certainly more than zero as that means it cannot happen and, it clearly did happen. It would have been difficult to
calculate because of the very limited historical data available but a working estimate could have been made and probably was to a limited degree,
(hence the claims that they were designed to sustain "multiple 707 impacts"). In the example of the marbles the probability certainly is zero, not
because it has never happened before but because there are no red marbles in the bowl so the condition where a red marble can be selected cannot
occur.

Originally posted by shindigger
But the towers fell in an IDENTICAL manner.

No they didn't, you've already identified that the tower that was hit first fell later so there must have been some diferent mechanics at work in
some respect at least.

However, two essentially identical structures were damaged in very similar ways so a very similar failure mode could well be expected although it
would be by no means certain.

As for probability well it was certainly more than zero as that means it cannot happen and, it clearly did happen. It would have been difficult to
calculate because of the very limited historical data available but a working estimate could have been made and probably was to a limited degree,
(hence the claims that they were designed to sustain "multiple 707 impacts"). In the example of the marbles the probability certainly is zero, not
because it has never happened before but because there are no red marbles in the bowl so the condition where a red marble can be selected cannot
occur.

[edit on 21-2-2007 by timeless test]

Please point out, given the overall scale and magnitude of the event, the main differences in the way the towers fell.
I saw them both fall straight down. Both shooting heavy debris straight up in the air and sideways over large distances.
The main thrust here is that they didnt topple or semi demolish, they crumbled like dry soil in your hand.

Originally posted by shindigger
In such a supposedly "random" and unexpected event?
If the planes hit the 2 towers at differing angles,heights and velocities, why is the speed and nature of both towers collapse identical?

If the steel (as the BBC say) was weakened to the point of collapse by the heat, why did the 2nd tower to be hit, fall first?
Leaving aside any "temperature required" issues.

Let's get back to some common sense here.

First, the "chances" are 100%. Both towers DID collapse. Both towers suffered very similar damage. Therefore, it is not surprising that both met
the same fate.

Further, there were noticeable differences in the collapses, which would account for variations in the *precise* damage suffered by each tower.

Finally, there is nothing in history to compare this event to.

However, that's exactly the reason why it's incredibly strange that the government failed to legitimately investigate the *possibility* that the
collapses were helped along by other terrorist activity, like bombs also being planted inside the buildings. The proverbial "black boxes" of the
WTCs were the steel beams that failed. But the government shipped out the steel and didn't properly investigate, or document the crime scene.

So how is it that the government *knows* that there were no explosives?

The structure of the tower itself imploded...steel anneals as it is heated, or softens. Steel loses its hardness and strenth...add the damage of the
impact, and there were somer eports that inferior fire retardent was used on the steel itself during construction.

you will find anything you wish if you look hard enough, but it is not reasonable or logical. Planes hit the tower, and they collapsed soon after.
The need to have it be more than sick fanatics creates this cottage industry of conspiracy.

Originally posted by jtma508
The original question was 'what are the chances'. I interpret that to mean 'what is the probability...'. That being the case, the answer is 0.
Since there had never been a collapse of this kind of structure ever before there would be no precedent against which to calculate the probability.
Therefore the answer is 0.

An example: You have a bowl with a random number of black and white marbles in it. You select single marbles and note their color returning them to
the bowl. After some number of selections you can calculate the probability of choosing a black or white marble (based upon your earlier selections).
If asked, 'what is the probability of selecting a red marble your answer would be: 0. Never happened before so has 0 probability.

Question. What about for a certain number of black and red marbles? Would the probability be 0 if there were 2 of each? Because of our understanding
now, I don't think we need to have something to have happened before in order to calcuate a probablity of it happening again. Just because 2 towers
have not collapsed in a certain way before it does not mean that we cannot calculate a probabilty of 2 towers falling in a certain way. Some physics
and maths is all that is required to calcuate a probability of wether it is possible for 2 towers to fall the same way if hit in different places
at different angles and velocities. I am sure some physics that we know of now have probabilities without them actually happening. Just my
opinion.

Given that September 11th was not a windy day, and that there were nt throngs of people in the upper floors, the critical load ratio was probably
well over 10, meaning that more than nine-tenths of the columns at the same level would have to fail before the weight of the top could
have overcome the support capacity of the remaining columns.

the bold and underline is my emphasis...for the purpose of sweeping away the CT pap about pre-installed demo charges or thermite
'cutters' on the interior core columns.
the determination is that 9-10s of all the structural components which formed the intended living space unit... the exterior, the core columns, the
floor/roof trusses or the connectors, all were maxed out or failed on the same floor (or call it a Unit).

On February 13, 1965, real estate baron Lawrence Wein called reporters to his office to charge that the design of the Twin Towers was structurally
unsound.
[...]
Richard Roth, partner at Emery Roth & Sons, the architectural firm that was designing the Twin Towers, fired back with a three-page
telegram...

?? Why was there such an 'excessive' response?
to a wild and unsubstantiated claim by a real-estate mogul, who was not an engineer...
but who was probably just badmouthing the project and property which he (Lawrence Wein) did not own,
and out of a self interest to promote his office holdings, on the market at the time.
OR, did this reflexive attack on Mr Wein, stem from 'something' hidden about the WTC Towers and WTC Conplex, which was never meant to ever see the
light of day?

===== ====== =====

as i see it, the towers survived the initial impact,
but what went wrong, was that unanticipated zealots
would deliberately ram into the WTC towers
to take out the core columns.

then the engineering overlooked the weakest links in the chain,
which was the floor connections to the perimeter 'columns' (aka walls)

the concept of stacking boxes atop one another,
and having a 'unit' tie into the 'unit' above
and with alternating pattern, into the 'unit' below,
a seeming flexible 'spinal-cord' type of building would result

my guess is that mr. Lawrence Wein intuited the weakest-link model,
as there were ?unfounded? doomsday predictions back in the late '60s
that the towers would collapse like a house of cards, one day.

Originally posted by Mechanic 32
Okay, I suppose someone should also throw into the mix, in addition to the twin towers collapsing...

WTC7 collapsing.

Not to mention the mysteries still surrounding the Pentagon,

and whether or not the other plane was shot down in Pennsylvania or crashed due to heroic passengers.

Not to mention the coincidental NORAD exercises going on that day.

I wonder what the probabilities would be for all of the events combined.

Would be a mind boggling number, to say the least.

2 cents.

I'll try to help.

There were these planes see and they got hijacked then crashed into WTC 1&2 and the Pentagon. One plane crashed in a field possbly due to heroic
counter terrorism measures of passengers. I am surprised you did not know it has been on the news.

7 fellover because it was designed as an office block and not a nuclear bunker. Therefore its resilience to impact from large amounts of debris was
suspect.

The Norad exercises were as you indicate a coincidence.

Regarding probability my math is poor but as I see it, if something has happened it can't be impossible? So it nears the probable term more than
improbable

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